Jonny Wilkinson missed a long-range penalty in the 79th minute as Toulon and Clermont drew 26-26 in the Top 14.
Wilkinson opened the scoring with a 40-metre penalty before Nakaitaci grabbed his first try of the afternoon, going under the posts after Sebastian Tillous-Borde lost possession.
Toulon immediately responded with a try in the corner from Maxime Mermoz, converted by Wilkinson.
The weakened Clermont side responded with 13 unanswered points, fly-half Mike Delany kicking two penalties before Nakaitaci grabbed his second try - Wilkinson hitting back with a penalty to leave the score at 13-20 by half-time.
An interception try from Alexis Palisson brought Toulon level after the break, before replacement Matt Giteau put the hosts in front.
Delany and replacement Anthony Floch both added penalties for Clermont with Giteau levelling the scores at 26-26 as time ran out - Wilkinson's chance to win the match falling short.
Tries: Mermoz, Palisson
Cons: Wilkinson 2
Pens: Wilkinson 2, Giteau 2
Tries: Nakaitaci 2
Cons: Delany 2
Pens: Delany 2, Floch 2
Yellow Card: Chouly
Toulon: 15 Delon Armitage, 14 Rudi Wulf, 13 Mathieu Bastareaud, 12 Matt Giteau, 11 Alexis Palisson, 10 Jonny Wilkinson (c), 9 SÃ©bastien Tillous-Borde, 8 Chris Masoe, 7 Steffon Armitage, 6 Juan Fernandez Lobbe, 5 Nick Kennedy, 4 Bakkies Botha, 3 Carl Hayman, 2 Sebastien Bruno, 1 Andrew Sheridan.
Replacements: 16 Mickael Ivaldi, 17 Gethin Jenkins, 18 Levan Chilachava, 19 Jocelino Suta, 20 Vincent Martin, 21 Maxime Mermoz, 22 Nicolas Durand, 23 Joe van Niekerk.
Clermont: 15 Jean-Marcel Buttin, 14 Noa Nakaitaci, 13 Benson Stanley, 12 Regan King, 11 Julien Malzieu, 10 Mike Delany, 9 Ludovic Radoslavjevic, 8 Elvis Vermeulen, 7 Alexandre Lapandry, 6 Damien Chouly, 5 Loic Jacquet, 4 Julien Pierre, 3 Clement Ric, 2 Ti'i Paulo, 1 Raphael Chaume.
Replacements: 16 Vincent Debaty, 17 Benoit Cabello, 18 Daniel Kotze, 19 Viktor Kolelishvili, 20 Baptiste Hezard, 21 Kevin Senio, 22 Anthony Floch, 23 Wesley Fofana.
Referee: Jean-Luc Rebollal